1. Field of the Invention
The present invention relates to a method of managing a code identifying a wireless device in a wireless telecommunications system, and particularly, to such a method advantageously applicable to an ultra-wide band (UWB) wireless telecommunications system.
2. Description of the Background Art
The Multi-Band Orthogonal Frequency Division Multiplexing (OFDM) Alliance (MBOA), an industrial standardization organization, establishes a standard entitled “UWB MBOA MCA (Multiple Channel Access) V0.70”, regulating that telecommunications devices communicating with each other in a wireless telecommunications network forming a service area, referred to as an extended cluster, generate independently of each other at random a device identification (ID), which is referred to as DEVID and used for transmitting and receiving data. The device ID includes two octets ranging from 0x0200 to 0xFFFF. Note that “0x” means that a numeral and/or a letter following “0x” represent a hexadecimal number.
Any of the devices when intending to participate in the wireless network independently generates its device identification, and transmits the device identification on a beacon signal along with an eight-octet device address AD specifically allocated in advance to the device. In order to prevent the device identifications thus generated from competing or overlapping with each other, each device monitors the beacon signals transmitted from the other devices. Any device, when having found out that it uses the same device identification as another device, has to generate a new device identification.
The device identifications conflict or collision can be detected when one wireless device receives a beacon signal from another device and determines that the same device identification as itself is included in the beacon signal, or when beacon signals transmitted from first and second devices are determined by a third device as including the same device identification as each other.
For the former case, both of the devices, when having found the collision or conflict, will stop using the conflicting or competing device identifications, and generate new device identifications. For the latter case, the third device, when having found the collision, transmits to the first and second devices a beacon signal informing them of the collision to urge both of them to generate new device identifications.
It is thus ensured that the device identification specific to each device be unique throughout the wireless network in which the respective devices participate. The device identification may thus use not a long, eight-octet device address but a short, two-octet device identification, thereby allowing data transmission and reception.
U.S. patent application publication No. US 2005/0078646 A1 to Hong et al., teaches a method and a system that allow efficient communications between a child piconet coordinator (PNC) and a destination device. The method and system intend to allow a first device that belongs to a parent piconet and at the same time is the coordinator of a child piconet (child PNC) to appropriately communicate with a second device that exists in the parent piconet or in the child piconet even with their device identifications overlapping. Hong et al., further teaches that the method and system use an identifier for identifying the piconets and the device identifications specifically allocated to the respective devices to generate a command frame requesting a channel time or interval during which the first and second devices may communicate with each other, and at the first stage, transmit the command frame to the coordinator of the parent piconet (parent PNC), and at the second stager allow the parent PNC to which the command frame is transmitted to allocate the channel interval during which the first and second devices may communicate with each other, allowing at the third stage the first and second devices to transmit and receive data between them during the channel interval.
The “UWB MBOA MCA V0.70” standard defines that, when the device identifications conflict with each other, the conflicting device identifications are refrained from being used, and each device should generate a new device identification. The standard fails, however, to specifically define how to generate a new device identification. If a use is made of, for example, each device simply setting device identifications sequentially from 0x0200 or simply incrementing device identifications by one upon conflict or collision occurring, collisions would occur more frequently, thus adversely affecting the actual data transmitting and receiving.